Taylor: What we know, and don’t know yet

How, in fact, do we know anything?…And yet I also know that almost everything I know will probably turn out to be wrong.

An acquaintance declared recently: “I’m proud that our Canadian money says, ‘In God we trust!’”

Except that it doesn’t. American currency does; Canadian doesn’t.

No one challenged his remark, because the rules of the session precluded setting people straight. Every viewpoint was accepted, as that person’s perspective. But I’m sure, if anyone had challenged his assertion, he would have replied: “When did they change it? I know it was there!”

As American humorist Josh Billings once said: “It ain’t what we don’t know that gives us trouble, it’s what we know that ain’t so.”

You thought Mark Twain said that, didn’t you? Nope. As Billings might say: “’T’ain’t so.”

I’m no fan of Donald Rumsfeld, but I think Rumsfeld unintentionally scored a bullseye when he pontificated: “There are known knowns; there are things we know that we know. There are known unknowns; that is to say, there are things that we now know we don’t know. But there are also unknown unknowns—there are things we do not know we don’t know.”

How, in fact, do we know anything?

Three centuries ago, Bishop George Berkeley theorized that we can only know things through our physical senses—sight, hearing, touch, taste and smell. Therefore, he reasoned, there is no objective reality. Reality exists only in our perceptions.

Dictionary writer Samuel Johnson derided Berkeley’s idealism by launching a mighty kick at a rock. “Thus do I refute Berkeley,” he is supposed to have declared as he hopped around clutching his foot.

And yet there are times when I know I know something. I know that my memory of a particular event is accurate. I know that a word overheard in someone’s conversation has special meaning for me. I know that in an insight, all the pieces click into place, like the tumblers in a combination lock.

And yet I also know that almost everything I know will probably turn out to be wrong. Medicine keeps developing new health guidelines that replace previous guidelines. Quantum physics tells me that the chair I sit on isn’t a solid object but a collection of energy fields. Mathematics may already have proved that two and two isn’t always four.

Once, everyone knew the world was flat, and the centre of the universe. The Bible was the infallible word of God. The Earth was created to serve human needs.

Things change. So do we.

Philosophically, the encyclopedia tells me, I subscribe to something called “falibilism”. It assumes that we could be wrong about what we know and/or believe, even if current evidence justifies us in holding those convictions.

It doesn’t mean abandoning the knowledge we have. Or believing, like Bishop Berkeley, that we can never know anything beyond our own senses. Or even denying the value of pursuing truth or meaning, because whatever we learn will be superseded anyway.

It certainly doesn’t mean that there are no truths.

It simply means being open to new evidence that might cause us to change our minds.

I like a couple of wry lines from poet Hilaire Belloc:

“Oh! let us never, never doubt

What nobody is sure about!”